This invention relates generally to wire clamp assemblies for electrical terminals and more particularly to a screw and washer wire clamp assembly for holding a wire in engagement with a generally planar terminal member surface, of a terminal block or the like.
Screw and washer type clamping assemblies including a screw for threadably engaging an internally threaded terminal member and a clamping washer advanced by the screw to clamp a wire to the terminal member surface are known in the art. For example, attention is directed to U.S. Pat. Nos. 3,177,456 and 3,816,820 which disclose this type of arrangement. Many of the clamping washer members heretofore devised, however, allow some lateral or axial movement or twisting of the wire even after the clamping thereof, which may lead to mechanical or electrical failure of the connection. Other clamping members provide a secure connection only if great care and effort are taken in positioning the wire and while advancing the screw and washer assembly to make the connection. Also, many clamping members are designed for connecting wires in only a limited range of sizes and moreover, many connectors are inoperable in cases when two wires of different sizes are to be connected to the same terminal. Thus, many of the prior art clamping devices are not wholly satisfactory in use, as they require substantial time and effort in establishing mechanically and electrically acceptable connections, and furthermore offer a substantial opportunity for error in selecting the proper device for the wire size to be connected. Various clamping washers designed for use in such assemblies, in an attempt to alleviate some of these problems, are relatively complex in form, and correspondingly difficult and expensive to manufacture. As such, there existed a need for a more dependable, more versatile, and less expensive terminal washer, which need it is believed is filled by the present invention.